This study compared the effects of formulations and methods of hydrogel application on the survival and initial seedling growth of physic nut (Jatropha curcas L.). The study was conducted in Pato Bragado, PR during 2009 and 2010. The experimental design was in randomized blocks, arranged in a 5 x 2 factorial composed by five formulations of hydrogel (0, 2.5, 5.0, 7.5, and 10.0 g L-1) and two application methods (immersion of roots into hydrogel previously hydrated and application of 0.5 L directly in the planting hole). Measurements included the percentage of survival, seedling height and diameter increments, and number of branches three and eighteen months after planting. The analysis with three months data revealed significant effects (p < 0.05) of the tested hydrogel formulations with a linear adjustment for seedling survival from both application methods. The increments in seedling height and diameter showed a quadratic polynomial response for the application of 0.5 L of hydrogel per planting hole. After eighteen months, no significant difference (p > 0.05) was observed for the application methods or hydrogel formulations. The use of 0.5 L of a 7.0 g L-1 of hydrogel directly into the planting hole favored significantly the establishment of physic nut seedling and formulations above the suggested concentration reduced seedling growth in western Paraná.
Jatropha curcas L.; planting; hydrophillic polimer; dose
